<!DOCTYPE html>
<style>
  #target {
    position: relative;
    height: 50px;
    width: 50px;
    background-color: blue;
    animation: slide-right 1s linear forwards;
  }
  @keyframes slide-right {
    from { left: 0px; }
    to   { left: 10000px; }
  }
</style>
<div id="target"></div>
